Baaees et al. Conflict and Health (2021) 15:54 https://doi.org/10.1186/s13031-021-00394-1

RESEARCH IN PRACTICE Open Access Community-based surveillance in internally displaced people’s camps and urban settings during a complex emergency in in 2020 Manal Salem Omar Baaees1*, Jeremias D. Naiene1, Ali Ahmed Al-Waleedi2, Nasreen Salem Bin-Azoon2, Muhammad Fawad Khan1, Nuha Mahmoud1 and Altaf Musani1

Abstract Background: The need for early identification of coronavirus disease (COVID-19) cases in communities was high in Yemen during the first wave of the COVID-19 epidemic because most cases presenting to health facilities were severe. Early detection of cases would allow early interventions to interrupt the transmission chains. This study aimed to describe the implementation of community-based surveillance (CBS) in in internally displaced people (IDP) camps and urban settings in Yemen from 15 April 2020 to 30 September 2020. Methods: Following the Centers for Disease Control and Prevention guidance for evaluation of surveillance systems, we assessed the usefulness and acceptability of CBS. For acceptability, we calculated the proportion of trained volunteers who reported disease alerts. To assess the usefulness, we compared the alerts reported through the electronic diseases early warning system (eDEWS) with the alerts reported through CBS and described the response activities implemented. Results: In Al- , 18% (14/78) of the volunteers reported at least one alert. In IDP camps, 58% (18/31) of volunteers reported at least one alert. In Al-Mukalla City, CBS detected 49 alerts of influenza-like illness, whereas health facilities detected 561 cases of COVID-19. In IDP camps, CBS detected 91 alerts of influenza-like illness, compared to 10 alerts detected through eDEWS. In IDP camps, CBS detected three other syndromes besides influenza-like illness (febrile illness outbreak suspicion, acute diarrhoea, and skin disease). In IDP camps, public health actions were implemented for each disease detected and no further cases were reported. Conclusions: In Yemen, CBS was useful for detecting suspected outbreaks in IDP camps. CBS implementation did not yield expected results in general communities in urban areas in the early stage of the COVID-19 pandemic when little was known about the disease. In the urban setting, the system failed to detect suspected COVID-19 cases and other diseases despite the ongoing outbreaks reported through eDEWS. In Yemen, as in other , feasibility and acceptability studies should be conducted few months before CBS expansion in urban communities. The project should be expanded in IDP camps, by creating COVID-19 and other disease outbreak reporting sites. Keywords: Community-based surveillance, IDP camps, Urban settings, COVID-19, Complex emergency, Yemen

* Correspondence: [email protected] 1World Health Organization, Sana’a, Yemen Full list of author information is available at the end of the article

© The Author(s). 2021 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data. Baaees et al. Conflict and Health (2021) 15:54 Page 2 of 15

Background Several approaches of CBS have been used in develop- When the novel coronavirus disease (COVID-19) epi- ing countries [6, 14, 15]. However, there is no specific demic was confirmed in Yemen on 10 April 2020, the standard approach for CBS implementation, although had an insufficient number of trained rapid re- more than 79 unique surveillance systems have been de- sponse teams (RRTs) to investigate the suspected cases scribed in developing countries over the years [16]. To because of concurrent disease outbreaks, including chol- increase the chances of detecting COVID-19 cases in era, diphtheria, arboviral diseases and others [1, 2]. One communities in Yemen, an active CBS was performed by RRT was available in each to cover more than the community volunteers from MOPHP and partner 300,000 people, and most of the COVID-19 cases did organizations in urban communities, and in IDP camps. not report to the health facilities [1, 3]. The active CBS was done through door-to-door visits The surveillance system in Yemen is exclusively based targeting mainly people with influenza-like illness, unex- on the electronic diseases early warning system plained cluster of diseases, and acute public health (eDEWS), in which most health facilities are used as events. The general community health volunteers from reporting sites for epidemic-prone diseases. Data from (GCHVs) and IDP community health volun- the health facilities are reported in real-time and visual- teers (ICHVs) reported to their health facility focal ized at all levels, allowing early detection of abnormal points (HFFPs) the cases detected through active CBS. disease trends [3]. The rumours from the communities The HFFPs requested the RRTs deployment by the are detected by the health office (GHO) GHO when the cases met COVID-19 case definition, or through information provided by general public, media, cluster of cases or deaths. The cases not fulfilling the and others. After rumour detection, the GHO deploys above-mentioned criteria were referred to the nearest RRTs for investigation and response [1, 4]. RRTs are health facilities for treatment without deployment of Ministry of Public Health and Population (MOPHP) staff RRTs. Suspected COVID-19 cases in Yemen were de- supported by partners, each team comprising a phys- fined as any person with influenza-like illness and his- ician, surveillance officer, laboratory technician, environ- tory of travel or residence in affected areas in the past mental health officer and a risk communication officer 14 days before the symptom onset or any case of severe [1]. The initial response of the RRTs may include health influenza-like illness without a precise diagnosis. Con- promotion, chlorination of water, search and removal of firmed cases were cases with polymerase chain reaction mosquito breeding sites, and case management of mild test positive for COVID-19 infection [1]. Herein, we de- cases, depending on the disease investigated [4]. The ru- scribe the implementation of CBS in IDP camps and mours investigated by RRTs are also reported through urban settings in Yemen from 15 April 2020 to 30 Sep- eDEWS and published in the weekly bulletins produced tember 2020. To our knowledge, this is the first docu- by the MOPHP. mentation of CBS implementation in Yemen, and it More than 40,000 community volunteers recruited by provided evidence at the national level. The challenges national and international organizations were available and lessons learned can be considered before further in Yemen, and they mainly implemented health promo- expanding the project in Yemen and other countries tion activities [4]. These volunteers were also encour- with similar contexts. aged to report rumours of suspected outbreaks to the GHO to deploy RRTs [3]. Methods Active community surveillance is more effective in Setting identifying missed cases during a disease outbreak than The Republic of Yemen is a country in the Arabian Pen- passive surveillance, which is more useful before an out- insula that is subdivided into 23 governorates. The gov- break [5–8]. Active community surveillance to detect ernorates in Yemen are further subdivided into 333 missed epidemic-prone disease cases can be useful in [17]. Among the governorates, CBS in IDP Yemen, where 42% of the population require at least a camps was piloted in , Abyan, Lahj, and Taiz, 1-h drive to reach a hospital [9]. Event-based surveil- while Hadramout piloted CBS in urban setting (Fig. 1) lance, including community-based surveillance (CBS) [17–19]. This paper describes the CBS pilot in Yemen may allow the earliest detection of outbreaks, especially in all the governorates and districts where it was cases not reported to the health facilities [10]. implemented. Cases among internally displaced people (IDP) may Al-Mukalla in Hadramout governorate was easily be missed owing to limited access to health facil- selected for CBS piloting to target the general population ities for self-reporting [11, 12]. Because of the ongoing in urban settings as part of a public health response to armed conflict and natural disasters in Yemen, around the first case of COVID-19 in Yemen. Although the case 172,386 IDPs were present in different governorates in was reported in As Shikhr district, most of the patient’s the country from January to December 2020 [13]. contacts were in Al-Mukalla city. Among the 10 zones, Baaees et al. Conflict and Health (2021) 15:54 Page 3 of 15

Fig. 1 Areas of implementation of community-based surveillance pilot in Yemen, 2020

Fig. 2 Final structure of community-based surveillance pilot, Yemen, 2020 Baaees et al. Conflict and Health (2021) 15:54 Page 4 of 15

we performed CBS in four zones wherein the contacts of case definition was “any case of acute onset of fever, the index cases were located (Fig. 2). cough, and difficult breathing”. The community case Al-Mukalla city is an urban area and one of the 28 dis- definition for unexplained clusters of diseases or public tricts of Hadramout governorate, which has 10 zones health events was defined as “unknown community [18]. In 2017, the total population in Al-Mukalla city health problems affecting two or more people”. was estimated to be 264,100 inhabitants projected from the 2004 census, with an average of 7 people per house- Data source and analysis hold [18, 20]. The four zones selected for CBS pilot had We examined the lists of focal points and volunteers a total population of 97,175 inhabitants (Table 1). provided by MOPHP and partners. We matched the The CBS pilot targeting the IDP camps was performed abovementioned lists with attendance lists of the train- in Aden, Lahj, Abyan, and Taizz because these - ings to identify the number of people trained for CBS. ates were accessible. Among the six governorates with Moreover, we examined all alert triggers, line lists, the highest number of IDPs in Yemen, , Al- weekly narrative, weekly aggregated and training reports Dhale’e, and Hudaydah were not easily accessible from produced from 15 April 2020 to 30 September 2020. Aden owing to ongoing armed conflicts. In each of the This report describes the selection process, including the selected governorates, we selected the two districts with number of volunteers selected, selection criteria, and dis- higher numbers of IDP camps and households, except tribution of households per volunteer. We also describe Aden where IDP camps were concentrated in only one the training timeliness, topics covered, the number of district, resulting in a total of seven districts selected for people trained, active CBS and referral process, incen- CBS (Table 2). tives and personal protective equipment (PPEs) pro- According to the International Organization for Mi- vided, and reporting system. Summary statistics, gration (IOM)‘s rapid displacement tracking (RDT) sys- including the number of cases, distribution by sex, age tem, Marib, Al-Dhale’e, Taizz, Hudaydah, Lahj, and group, geographical location, epidemiological week, and Abyan were the six governorates in Yemen with higher proportion of severe cases, were calculated. Data in the numbers of IDPs owing to active ongoing armed con- line lists were compiled and analysed using Microsoft flict. In the beginning of CBS project, on 15 April 2020, Excel. We manually extracted data of confirmed 71,304 IDP (11,884 households) were present in Yemen, COVID-19 cases in Yemen from the daily reports avail- and 14% of them were accommodated in tents, schools, able from the official twitter account of the MOPHP. and public buildings [13]. The others were welcomed by Weekly narrative reports were produced by the HFFPs host families or rent houses in the general community. and highlighted in bullet points to their challenges and The seven districts that activated CBS had 32 IDP camps the volunteers under their supervisions. We also exam- with a total population of 1806 inhabitants residing in ined the Yemen eDEWS bulletins from week 19, 2020 to the camps (Table 2). week 40, 2020 to extract the number of alerts detected through the system. The bulletins were publicly available Alert triggers on the Yemen Health Cluster website. The IDP demo- To make the CBS as simple as possible, while keeping it graphic information was obtained from the dataset of sensitive enough to detect suspected COVID-19 cases the RDT system from 1 January 2020 to 4 July 2020, without missing other health-related problems in the which was available publicly in the IOM website. From community, the GCHVs and ICHVs were requested to this dataset, we extracted the data of IDPs that were report only two types of alerts. These include alerts of present when the first alert trigger was submitted by the influenza-like illness and unexplained clusters of diseases ICHVs on 28 June 2020. or public health events. The standard case definitions were simplified into community case definition used as an alert trigger. The influenza-like illnesses community Attributes of CBS system We followed the steps suggested in the World Health Table 1 Trained volunteers in CBS in Hadramout, Yemen, 2020 Organization (WHO) regional office for guide for Zone Population Number of volunteers establishing a CBS in Yemen due to unavailability of spe- Buwaish 6177 18 cific guidelines for developing countries from the East- ern Mediterranean [21]. We used the Centers for Fowa 13,168 20 Disease Control and Prevention guidance for evaluation Al-Deis 33,226 19 of surveillance systems to select the attributes of CBS Alsharej 44,604 21 presented in our report [22]. Based on the information Total 97,175 78 collected during the CBS implementation in Yemen, we CBS community-based surveillance selected the attributes acceptability and usefulness. Baaees et al. Conflict and Health (2021) 15:54 Page 5 of 15

Table 2 Number of staff trained and CBS implementation in IDP camps by district in Yemen, 2020 District Population Number Number of Number of Average Number of Number Number of Status in IDP of IDP IDP IDP number of volunteers of ICHVs volunteers who of CBSe camps camps householdsa households households trainedc trained submitted at least in Campsb per camp one reportd Taizz Governorate Ash- 182 7 45 26 4 18 6 2 Activated Shamayatayn Al Ma’afer 119 6 66 17 3 6 5 3 Activated Other 490 12 1505 70 6 42 12 0 Not Districts Activated Zingibar 210 2 139 30 15 2 2 1 Activated Khanfir 406 5 86 58 12 5 5 2 Activated Other 119 4 702 17 4 11 11 0 Not Districts Activated Lahj Governorate Tuban 84 5 23 12 2 5 4 3 Activated Al Hawtah 105 2 15 15 8 3 2 2 Activated Other 140 0 795 20 0 11 0 0 Not Districts Activated Aden Governorate Craiter 700 5 114 100 20 12 7 5 Activated Other 28 2 131 4 2 15 5 0 Not Districts Activated IDP internally displaced persons, CBS community-based surveillance, ICHV IDP camp community health volunteer aIncludes households outside of IDP camps, mixed with general communities, such as in private houses, host family houses, or second homes. Each household had an average of 7 people bincludes tents, public, and private buildings cThe training also targeted volunteers to cover IDPs in the host communities and refugees, although they did not submit any report and CBS was not activated in those areas dOnly ICHVs submitted reports, and not reports were submitted by the volunteers that were supposed to cover the IDPs in the host communities and refugees eDespite the trainings targeting all the districts from the 4 governorates, only the 2 districts with a higher number of households were selected to activate CBS

Acceptability Usefulness We considered the acceptability of CBS as the willing- We considered CBS useful if it satisfactorily detected ness of the volunteers, health facility focal points, local suspected outbreaks and if the data collected led to the authorities, organizations and the public to participate in implementation of public health actions to control out- the project [22]. To assess the acceptability, we calcu- breaks [22]. To assess the ability of the CBS to detect lated the proportion of ICHVs and GCHVs who submit- outbreaks, we compared the number of alerts reported ted at least one alert trigger to the HFFPs. We also to the eDEWS with the alerts reported by ICHVs and calculated the reporting rate of weekly aggregated re- GCHVs in the districts where CBS was activated. We ports, and weekly narrative reports submitted by the also described the public health actions taken for cases HFFPs to the governorate level. To estimate the number detected by ICHVs and GCHVs to assess the usefulness of weekly aggregated reports and weekly narrative re- of CBS. To understand the impact of public health ac- ports that were expected to be submitted by the HFFPs, tions, we counted the number of cases reported by the we multiplied the number of HFFPs by the number of ICHVs and GCHVs after the actions were taken. weeks of CBS implementation. Therefore, the four HFFPs from IDP camps were expected to submit 52 Results weekly reports from the time of CBS activation in IDP Key interventions camps on week 27, 2020 to the end of the project on Selection of CBS focal points and volunteers week 40, 2020. The four HFFPs from Al-Mukalla City Community volunteers previously conducting commu- were expected to submit 84 weekly reports from the ac- nity for development (C4D) activities under the United tivation of CBS in an urban setting in week 19, 2020 to Nations Children’s Fund (UNICEF) were selected to per- week 40, 2020. form CBS activities in urban setting. Community Baaees et al. Conflict and Health (2021) 15:54 Page 6 of 15

volunteers previously conducting health promotion ac- from the IDP camps. Any person with epidemiological tivities under the Camp Coordination and Camp Man- background was eligible for HFFP. agement (CCCM) cluster partners were selected to perform CBS activities in IDP camps. The volunteers Training of governorate, district, health facility and were previously conducting longstanding activities and community level staff they were selected to perform CBS activities in their area On 16 April 2020, the WHO conducted a one-day train- of residence. A total of 80 community volunteers sup- ing of CBS in urban setting governorate level team ported by UNICEF were available and initially selected trainers. The roll out training was conducted by the gov- by the GHO from Hadramout to cover the four zones in ernorate focal point on 4 May 2020 and targeted district Al-Mukalla City, namely Al Share, Al-Deis, Buwaish and surveillance officers and HFFPs from Al-Mukalla city Fowah zones, with 20 volunteers in each zone. Accord- and three other districts in Hadramout governorate. ing to the number of houses in the zones, each volunteer From 27 to 29 April 2020, IDP camp HFFPs from Aden, would cover 180 houses, each of them to be visited Abyan, Lahj, and Taiz were trained. The ICHVs were monthly. A total of 130 ICHVs were identified and se- trained from 4 to 6 May 2020 by HFFPs, and the lected by the CCCM cluster partners in coordination GCHVs were trained from 6 to 8 May 2020 (Fig. 3). The with the Executive Unit of IDPs, the governmental unit training for both CBS in urban settings and IDP camps responsible for linking the government with the organi- covered the basics of CBS, including key definitions, ob- zations supporting IDPs. This allowed each IDP camp to jectives, structure, roles and responsibilities, strategy, be covered by at least one ICHV, regardless of the num- and others. The training also covered overview of re- ber of households in the camp. Therefore, the number spiratory illnesses, community case definitions, active of households per ICHV ranged from 2 to 20 (Table 2). CBS, reporting tools, and timeliness of notification and Any person able to read and write, aged more than 18 reporting. Brochures with health education messages years, residing in the community or IDP camp and pre- and alert triggers were printed and distributed to all viously performing other health related tasks such as GCHVs, ICHVs and focal points. C4D or health promotion activities, was eligible to be A total of 14 district level staff from four districts were GCHV or ICHV. The HFFPs from Al-Mukalla city were trained in CBS in Hadramout governorate. Additionally, selected by the GHO from Hadramout, while the 78 of 80 GCHVs selected in Al-Mukalla city district MOPHP national CBS coordinator selected the HFFPs were trained, of whom 67% (n = 52) were women (Ta- bles 3 and 4). Moreover, 175 ICHVs were trained, of

Fig. 3 Chronology of the main trainings and events related to CBS in Yemen, 2020 Baaees et al. Conflict and Health (2021) 15:54 Page 7 of 15

Table 3 Distribution of the staff trained in CBS by district in Hadramout, Yemen, 2020 District Al-Mukalla city As Shikhr Ad Dis Ar Raydah Wa Qusayar Total District surveillance officers trained in CBS 1 1 1 1 4 Health facility focal points trained 4 2 2 2 10 Community volunteers trained on CBSa 78000 78 Number of zones selected for CBS 4 0 0 0 4 Hadramout governorate level surveillance officers trained in CBS NA NA NA NA 6b Status of CBS Activated Not Activated Not Activated Not Activated CBS community-based surveillance, NA not applicable a20 volunteers trained for each zone, except two zones were 19 volunteers were trained in each bOnly includes the surveillance officers trained at the governorate level, excluding the ones trained at the district level whom 31 were assigned to be ICHVs in areas where alert trigger form used by the GCHVs and ICHVs in- CBS was activated. Of the ICHVs trained, 74% (n = 130) cluded the same information, namely the date of report- were men. All HFFPs selected for community surveil- ing, demographic information of the patient, duration of lance in IDP camps were medical doctors, whereas those illness, main signs and symptoms and how the case was in Hadramout governorate were non-clinicians with detected (see Additional file 1 and Additional file 2). basic training in public health surveillance. The HFFPs assessed whether the cases required further investigation by RRTs, direct referral to a health facility, Organisation of CBS and referral or home stay (Fig. 4). The assessment was done through GCHVs and ICHVs actively searched for suspected phone calls to the volunteers and patients to obtain add- COVID-19 cases and unusual cluster of diseases in com- itional clinical information and classify the cases accord- munities and IDP camps respectively through daily ing to their severity and public health impact. Potentially door-to-door visits and weekly community meetings. severe cases were also visited physically after phone calls. The GCHVs and ICHVs were requested to conduct A photo of the alert trigger form was also sent in real weekly meetings with the communities to auscultate the time to the HFFP via a WhatsApp message. The HFFP main challenges faced by the communities and to detect compiled the alert triggers variables in a line list and cases missed during door-to-door visits. Moreover, the weekly aggregated form. The weekly aggregated form in- GCHVs and ICHVs performed health education activ- cluded the total number of cases, deaths, cases by age ities during the door-to-door visits and community group, number of cases by disease, number of cases dis- meetings. Transportation allowance was provided by the covered through door-to-door visits, community meet- WHO to all trained GCHVs and ICHVs to facilitate ings and others, and number of cases referred to RRTs, their movement. The allowance for GCHVs and ICHVs health facilities and advised to stay home (see Add- was calculated based on the rate applied by MOPHP and itional file 3). The line lists contained all the variables in- the distance travelled. UNICEF and CCCM partners pro- cluded in the alert trigger form, detailed signs and vided PPEs to the GCHVs and ICHVs respectively for symptoms, case classification in mild, moderate, or se- the activities that they had previously performed before vere, and actions taken for each case. The GCHVs, the CBS pilot, including C4D and health promotion ac- ICHVs and HFFPs were also requested to produce a tivities. These PPEs included masks, gloves, face shields, weekly narrative report highlighting the main activities and gowns. Further, they were also used for CBS activ- implemented during the week and challenges faced in ities as no additional PPE was available due to the global bullet points. Credit for phone calls and internet was shortage. The GCHVs and ICHVs were oriented to fol- provided by WHO to the GCHVs, ICHVs and HFFPs. low all preventive measures, including physical distan- HFFPs provided feedback about the quality of the re- cing, always wearing PPEs while interacting with ports, accuracy of the alert triggers and findings of the household members and not entering the houses. initial assessment of the cases to the GCHVs and ICHVs during weekly coordination meetings. Data transmission and feedback Immediately after identifying suspected COVID-19 cases Reports submitted and the unusual cluster of diseases, the GCHVs and In Hadramout governorate, 18% (14/78) of trained ICHVs were responsible for contacting the HFFPs GCHVs submitted at least one alert trigger form to the through text messages or phone calls and filling in alert HFFP (Table 5). Among trained ICHVs in districts se- trigger forms with detailed information of the cases. The lected for CBS implementation, 58% (18/31) submitted Baaees et al. Conflict and Health (2021) 15:54 Page 8 of 15

Table 4 Demographic characteristics of staff trained in CBS in Yemen, 2020 Governorate District Zone/ Level Function Gender Background Site Male Female Total Medical Nurse Pharmacist Othersa Doctor Aden NA NA National CBS 01 11 0 0 0 Coordinator General CBS Hadramout Al-Mukalla NA Governorateb CBS 10 10 0 0 1 Coordinator Hadramout Al-Mukalla Buwaish Zone HFFP 1 0 1 0 1 0 0 Hadramout Al-Mukalla Al-Deis Zone HFFP 1 0 1 0 0 1 0 Hadramout Al-Mukalla Fowa Zone HFFP 0 1 1 0 1 0 1 Hadramout Al-Mukalla Alsharej Zone HFFP 0 1 1 0 0 0 1 Hadramout Al-Mukalla Buwaish Community GCHV 7 11 18 0 0 0 18 Hadramout Al-Mukalla Al-Deis Community GCHV 10 9 19 0 0 0 19 Hadramout Al-Mukalla Fowa Community GCHV 7 13 20 0 0 0 20 Hadramout Al-Mukalla Alsharej Community GCHV 2 19 21 0 0 0 21 CBS in IDPs/Refugee sites Aden NA NA Governorate HFFP 1 0 0 1 0 0 0 Lahj NA NA Governorate HFFP 1 0 0 1 0 0 0 Abyan NA NA Governorate HFFP 1 0 0 1 0 0 0 Taizz NA NA Governorate HFFP 1 0 0 1 0 0 0 Abyan Zingibar and Khanfir NA IDP camp ICHV 14 4 18 0 0 0 18 Aden Craiter NA IDP camp ICHV 18 9 27 0 0 0 27 Lahj Tuban and Al Hawtah NA IDP camp ICHV 11 8 19 0 0 0 19 Al-Dhale’e Ad-Dhale, Qa’atabah, Al-Hussein, Al- NA Community NAc 26 3 29 0 0 0 29 Azarik Hudaydah Khokha, Tuhayta NA Community NAc 13 3 16 0 0 0 16 Taizz Ash-Shamayatayn and Almaafer NA IDP camp ICHV 48 18 66 0 0 0 66 NA not applicable, CBS community-based surveillance, IDP internally displaced person, GCHV general community health volunteer, HFFP health facility focal point, ICHV IDP camp community health volunteer aParamedics, physician assistants, and non-clinicians (including a bachelor’s degree in public health) with a formal training in public health surveillance bWas in charge also for Al-Mukalla district because it was the only district activating CBS in the Hadramout governorate cThe volunteers were trained to work in CBS targeting the IDP in host communities outside of the camps, but CBS was not activated in this target groups at least one alert trigger form (Table 2). The HFFPs from health events. During the same surveillance period, six IDP camps submitted 100% of the expected 52 weekly main groups of disease alerts, namely influenza-like, aggregated reports and 10% (n = 5) weekly narrative re- chronic respiratory, acute febrile illnesses, acute diar- ports. The HFFPs from Al-Mukalla city submitted 65% rhoea, skin disease, and abdominal distension, were de- (n = 55) of the expected 84 weekly aggregated reports tected by ICHVs (Fig. 5). The alerts of chronic and 1% (n = 1) of weekly narrative reports. respiratory illness and abdominal distention had no cri- teria to be reported by the ICHVs as they did not consti- Alerts detected through CBS and eDEWS tute a cluster of a disease involving two or more people. Overall alerts From 10 May 2020 to 24 September 2020, a total of 49 Influenza-like illness and COVID-19 alerts were reported by the GCHVs, all of them From the 49 alerts of influenza-like illness detected by influenza-like illnesses. The GCHVs reported no deaths GCHVs from 10 May 2020 to 24 September 2020, infor- during the same surveillance period. All cases in mation about the severity of the cases, and cases making Hadramout governorate were detected during door-to- suspected COVID-19 case definition were not docu- door visits and were referred to health facilities and the mented in the line list from Al-Mukalla city. The Buwa- RRTs were not deployed. From 28 June 2020, when the ish district reported 49% of all cases and from all age first alert was reported in IDP camps, to 30 September groups (Table 6). During the same surveillance period, a 2020, 133 alerts were reported by the ICHVs, 69% (n = total of 561 confirmed COVID-19 cases, including 224 92) of them being the influenza-like illness and 31% (n = deaths (case fatality ratio = 40%) were detected by health 41) being unexplained clusters of diseases or public facilities in Al-Mukalla city (Fig. 6). Baaees et al. Conflict and Health (2021) 15:54 Page 9 of 15

Fig. 4 Actions taken to alert triggers identified through community-based surveillance, Yemen, 2020

Influenza-like illnesses were the most reported alerts dengue fever outbreak. Alerts of suspected measles, per- by ICHVs, with 92 cases and 0 deaths reported from 9 tussis, diphtheria, viral haemorrhagic fever and cholera IDP camps and 5 districts in Aden, Lahj, and Taiz gover- were also detected through eDEWS during the surveil- norates (Fig. 7). None of them made suspected COVID- lance period, each of them with less than 10 cases 19 case definition. reported. Among the 92 reported cases, 22% (n = 20) were severe The ICHVs detected alerts of 25 cases and 1 death and 78% (n = 72) were mild cases. Among the mild cases, owing to acute febrile illness from 7 camps and 5 dis- 35% (n = 25) were advised to receive care at home. Fur- tricts in Abyan, Aden, and Lahj governorates. All the thermore, among 92 reported cases, 73% (n = 67), in- cases were mild, barring a severe case reported in Lahj cluding all severe cases, were referred to health facilities. governorate, which ended in death. Furthermore, all All cases of influenza-like illness were sporadic, and cases were referred to health facilities for treatment. none of them was investigated by RRTs. During the im- During week 32, one cluster of seven cases of acute fe- plementation of CBS in IDP camps, 10 COVID-19 cases brile illness was detected in a camp in Abyan governor- were detected by the health facilities from three districts ate, affecting children aged < 10 years. The RRTs were implementing CBS: five cases in Craiter district in Aden called for investigation and response. All the cases were governorate, two cases in Ash-Shamayatayn, and two mild, with isolated fever, without other associated symp- cases in Al Ma’afer districts, both in . toms. Four cases were females, and 4 were children aged None of the cases were referred from IDP camps. < 5 years. A cluster of six cases (no deaths) of acute diarrhoea Unexplained cluster of diseases was detected by ICHVs in a camp in Aden governorate Although the GCHVs did not detect cluster of diseases during week 32. All the cases were mild and were re- or public health events besides influenza-like illness, 284 ported in four children aged < 5 years and two adults of alerts of acute febrile illness were detected through 28 and 35 years. The RRTs were called for investigation eDEWS in Al-Mukalla city. The city was affected by a and response.

Table 5 Community report submission through CBS in Hadramout, Yemen, 2020 Zone Number of volunteers who sent at least one alert trigger Percentage of volunteers who sent alert triggers Buwaish 2 11% Fowa 4 20% Al-Deis 6 32% Alsharej 2 10% Total 14 18% CBS community-based surveillance Baaees et al. Conflict and Health (2021) 15:54 Page 10 of 15

Fig. 5 Alerts detected by volunteers from internally displaced people camps, Yemen, 2020

During weeks 27 and 32, ICHVs also detected two detected during community meetings. During the cluster of a mild skin disease in two camps in Aden gov- same surveillance period, all the districts imple- ernorate. The RRTs were called for investigation and re- menting CBS in IDP camp were affected by dengue sponse to the two clusters. Each of the clusters affected fever and cholera outbreaks. Those districts reported five people, with 80% of them (n = 8) being children aged a total of 334 alerts of acute febrile illness, 188 < 10 years and the remaining being two adults of 18 and alerts of acute watery diarrhoea, 12 alerts of pertus- 35 years (Fig. 8). sis and 10 alerts of influenza-like illness through All cases of diseases detected by ICHVs were de- eDEWS during the period of CBS implementation. tected through household visits, except two cases of No alert of skin disease alerts were reported acute febrile illness and one case of skin disease through the eDEWS.

Table 6 Cases of influenza-like illness reported through CBS in Hadramout, Yemen, 2020 Al Share zone Al-Deis zone Buwaish zone Fowah zone Total Sex Female 4 2 6 0 12 Male 10 4 18 5 37 Total 14 6 24 5 49 Age group, years 0–42 0 1 0 3 5–91 1 4 1 7 10–19 3 2 3 0 8 20–29 1 1 4 0 6 30–39 3 2 3 0 8 40–49 2 0 1 1 4 50–59 2 0 4 2 8 >60 0 0 4 1 5 CBS community-based surveillance Baaees et al. Conflict and Health (2021) 15:54 Page 11 of 15

Fig. 6 Alerts of influenza-like illness detected through community-based surveillance, Yemen, 2020

Fig. 7 Acute febrile illness and influenza-like illness cases detected though community-based surveillance, 2020 Baaees et al. Conflict and Health (2021) 15:54 Page 12 of 15

Fig. 8 Weekly trends of diseases detected by volunteers from internally displaced people camps, 2020

Public health responses frequent lockdowns. HFFPs from IDP camps and ICHVs The cases of influenza-like illness in both IDP camps reported insufficient health facilities near the camps for and urban areas did not trigger the deployment of RRTs patient referral, difficulties in inter-camp movements and no specific public health actions were taken besides owing to weather conditions, limited community health the referral of the cases to the health facilities for further awareness, insufficient PPEs, and the lack of ambulances investigations. to transport cases to health facilities. In the IDP camps, the cluster of febrile illness, acute diarrhoea and skin diseases were responded by the Discussion RRTs. The response to the cluster of acute febrile illness The implementation of CBS in Yemen demonstrated to in Abyan governorate included the referral of the cases be more useful in IDP camps than in urban settings. In to the nearest health facility for further investigations, IDP camps, the system could detect suspected outbreaks health education to the families on mosquito-borne dis- and guided public health actions for control. However, it ease prevention and removal of potential mosquito failed to detect outbreaks in urban settings. The report- breeding sites around the houses. For the cluster of ing rate among GCHVs and HFFPs from Al-Mukalla acute diarrhoea cases in Aden governorate, the RRTs City was also low, suggesting low acceptability of CBS provided oral rehydration solutions to the households as among the staff. However, the acceptability among the all the cases were mild, besides the chlorination of the communities remained unclear from our findings. At drinking water and health education on prevention of least one alert trigger was submitted by 58% (18/31) of diarrheal diseases. The cases of skin disease detected in ICHVs, compared to 18% (14/78) of GCHVs in Al- Aden governorate were referred to the health facility for Mukalla city. The low reporting rates of CBS in Al- further investigation. Additionally, the RRTs provided Mukalla city may have been affected by low willingness health to the households on environmental cleaning, of the GCHVs and HFFPs to perform the activities, low personal hygiene, waste disposal, treatment of water and mentoring by the supervisors, and high refusal rates by others. No additional cases of the three diseases were re- the communities to provide the information. The higher ported in the camps after the public health actions were reporting rate of CBS in the IDP camps was likely be- taken. cause a few households were assigned to each ICHV (2– 20 per ICHV). IDP camp households likely trusted the Weekly narrative report findings ICHVs more because they resided in the same camp and The main challenges reported in Al-Mukalla city were were very well known. The average numbers of house- instances of household refusal to interact with GCHVs holds per GCHV in Al-Mukalla city was 180. Those owing to limited COVID-19 awareness, and the fear of number suggests that when CBS was activated, the GCHVs to participate in CBS owing to the lack of PPEs. GCHVs were probably not well known by the communi- Furthermore, other challenges reported in Hadramout ties and therefore were not received by households were limited GCHV knowledge about other diseases and owing to a fear of stigma [1]. Moreover, the assignment difficulties in performing door-to-door visits owing to of a high number of households per GCHV proved to be Baaees et al. Conflict and Health (2021) 15:54 Page 13 of 15

ineffective in Kenya owing to the limited time for inter- districts implementing CBS in IDP camps in Yemen action between volunteers and households [23]. During were facing outbreaks of dengue fever and cholera. How- the Ebola virus disease (EVD) outbreak in Sierra Leone, ever, Al-Mukalla city was also facing an outbreak of den- where the population per district is similar to that in gue fever, and 284 alerts of acute febrile illness were Yemen, CBS was successfully implemented because reported through eDEWS during the CBS implementa- many GCHVs were assigned for each district, with more tion period. Therefore, it would be expected alerts of fe- than 1000 volunteers per district. In Sierra Leone, CBS brile illness to be reported also by GCHVs. The early detected 30% (16/31) of the EVD cases, while 70% of the detection of suspected outbreaks of acute febrile illness, cases were detected through the regular surveillance sys- acute diarrhoea, and skin disease by the ICHVs allowed tem [14]. In addition, GCHVs in Al-Mukalla city prob- early deployment of RRTs, implementation of public ably had the same fear of interacting with people with health actions, and prevented the occurrence of add- suspected COVID-19 in activities such as the investiga- itional cases. Owing to insufficient trainings and inad- tion of community deaths, as the other health workers equate knowledge on other diseases, GCHVs from All- and RRTs owing to the lack of PPEs, as documented in Mukalla city reported only cases of influenza-like illness. the beginning of the pandemic in Yemen [1]. Although ICHVs, despite their insufficient trainings on other dis- PPEs were provided by UNICEF and CCCM partners, eases, were supervised by medical doctors, and few they were likely insufficient due to global shortage ob- ICHVs were assigned for each supervisor. In Hadramout served during the initial stages of COVID-19 pandemic governorate, the GCHVs were supervised by non- [24]. Confidentiality issues during the field activities may clinicians who had insufficient clinical knowledge despite also have contributed to fear of stigmatization and re- their public health background. fusal by the communities in Al-Mukalla city. The To allow for the identification of some challenges prior GCHVs were oriented to not enter the houses as a pre- to CBS implementation, project feasibility and commu- cautionary measure. This may have led to fear of the nity acceptability should be assessed [6]. However, in households that neighbours and other people in the Yemen, proper assessments were not performed because streets would hear their conversation with GCHVs. The the project was implemented as part of an emergency re- implementation of CBS in urban areas such as Al- sponse rather than as routine surveillance. The commu- Mukalla city is usually a challenge, requiring better co- nity and local authorities perceptions regarding CBS, ordination and an extensive education of communities, reasons of low reporting of cases to the health facilities, as demonstrated in Kenya and Yemen during the imple- proper calculation of resources and supplies needed, sus- mentation of integrated community case management tainability and other aspects should be considered before program in 2017 [23, 25]. the implementation of CBS [25, 28]. The variety of diseases alerts reported by ICHVs was The inadequate number of health facilities closer to also higher than those reported by GCHVs from Al- camps for patient referral, difficult inter-camp move- Mukalla city. While 14 GCHVs from Al-Mukalla city ments owing to weather conditions, and lack of ambu- only detected alerts of influenza-like illness, 18 ICHVs lances to transport the cases to the health facilities were detected five other syndromes, including suspected out- some of the challenges reported by ICHVs. In both IDP breaks of a febrile illness, acute diarrhoea, and skin dis- camps and urban settings, no feedback was provided ease, besides influenza-like illness. While GCHVs from laboratories and health facilities to CBS focal detected 49 alerts of influenza-like illness, the health fa- points. All suspected and confirmed cases were recorded cilities in the same area of CBS implementation reported in the generic line lists of routine surveillance, and the 561 confirmed cases of COVID-19, including 224 deaths cases reported through CBS were not specified. The (case fatality ratio = 40%). The high mortality of COVID- challenges reported in Yemen were previously docu- 19 in these areas indicates that the cases reached the mented during the implementation of the integrated health facility late and likely many cases remained in the community case management in 2017 and are similar to houses undetected by CBS [1]. Additionally, 90% (n = 92) those in other developing countries that attempted CBS of influenza-like illness alerts detected in the districts implementation [15, 25, 29]. The cost of setting set up a implementing CBS in IDP camps were reported by CBS system to support routine surveillance is usually ICHVs, compared to 10% (n = 10) of alerts detected huge, exceeding 1000,000 USD for the purchase of mo- through eDEWS during the same surveillance period. torbikes, organisation of trainings, purchase of mobile The number of people per household in IDP camps is phones and other items, excluding a monthly running usually higher than in host communities, and people in costs that may exceed 100,000 USD in a country such as the IDP camps live in precarious conditions [11]. There- Sierra Leone [14]. Most of the required items, including fore, different infectious disease outbreaks are usually mobile phones and computers, were not provided in anticipated among camp IDPs [26, 27]. Furthermore, the Yemen, which was another probable reason for the Baaees et al. Conflict and Health (2021) 15:54 Page 14 of 15

inadequate reporting from GCHVs in Al-Mukalla city. volunteers to be supervised by staff with clinical back- However, the impact of CBS in Yemen, especially in IDP ground; development of country specific CBS guidelines camps, was higher when matched with the funds used with community case definitions for other diseases with for its implementation that did not exceed 50,000 USD a risk for outbreak in Yemen; and the strengthening of for 6 months. Limited funds available for CBS continu- the link between CBS and routine surveillance systems ation is a very commonly reported challenge in other through feedbacks to HFFPs and community volunteers countries [29, 30]. on the outcome of patients and laboratory results. This study had several potential limitations. First, there were no available previous studies documenting CBS in Abbreviations Yemen and the studies from other countries in the re- C4D: Communication for development; CBS: Community-based surveillance; CCCM: Camp Coordination and Camp Management; COVID-19: Coronavirus gion were also few. Therefore, we could not compare disease - 19; eDEWS: Electronic disease Early Warning System; EVD: Ebola our findings with those from other Yemeni and Eastern virus disease; GCHV: General Community health volunteers; Mediterranean region studies. Second, some key indica- GHO: Governorate Health Office; HFFP: Health facility focal points; ICHV: IDP community health volunteer; IDP: Internally displaced people; tors of CBS such as question refusal rates in the commu- IOM: International Organization for Migration; MOPHP: Ministry of Public nities, timeliness of data reporting, and quantity of PPEs Health and Population; PPE: Personal protective equipment; RDT: Rapid provided to the volunteers and focal points, were not displacement tracking; RRT: Rapid Response Team; UNICEF: United Nations Children’s Fund; WHO: World Health Organization properly documented. Therefore, we were unable to as- sess some of the CBS attributes requiring these indica- tors. Third, the information on the number of Supplementary Information The online version contains supplementary material available at https://doi. households in IDP camps was not accurate because org/10.1186/s13031-021-00394-1. people were constantly arriving and leaving the camps. Therefore, some numbers observed by ICHVs did not Additional file 1. Alert trigger form in English translation. reflect those reported in RDT system. Thus, we adjusted Additional file 2. Alert trigger form in original version. the numbers in our report by matching with the num- Additional file 3. Weekly aggregated form. bers provided by the ICHVs. Despite these limitations, our findings will be useful for a further expansion of the Acknowledgements project in the future. We thank the United Nations Children’s Fund for provision of community volunteers in Hadramout governorate, production, and printing of Conclusions and future perspectives Community-based surveillance brochures to be used by the volunteers. We also thank the United Nations High Commissioner for Refugees for facilitat- CBS in Yemen demonstrated to be an extremely useful ing the selection of volunteers of IDP camps, and the Camp Coordination tool to detect outbreaks of respiratory and other diseases and Camp Management partners, namely Danish Refugee Council, Genera- in IDP camps, as it led to early detection and implemen- tions Without Qat, Agency for Technical Cooperation and Development, International Organization for Migration, Norwegian Refugee Council, and Ex- tation of public health actions which prevented the oc- ecutive Unit for IDPs for selecting the volunteers from IDP camps and refu- currence of further cases. CBS implementation in the gees and for facilitating the trainings. early stage of the COVID-19 pandemic, when little was known about the disease, did not yield expected results Disclaimer in general communities in urban areas. The system The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the World Health Organization and failed to detect suspected COVID-19 cases and other Ministry of Public Health and Population of Yemen. diseases in Al-Mukalla city despite the ongoing out- breaks in the same location reported through eDEWS. Authors’ contributions The ability of the staff, including the detection of dis- MSOB was a major contributor in conception and design, revised the manuscript critically for important intellectual content, analysed and eases in the communities was better among volunteers interpreted the data. JDN drafted the manuscript, analysed, and interpreted supervised by clinicians than among those supervised the data. AAA contributed to analysis and interpretation of data, revised the with staff without a clinical background. The acceptabil- manuscript critically for important intellectual content. NSBA, was a major contributor in acquisition of data, contributed to analysis and interpretation ity of CBS among the staff was higher in IDP camps of the data. MFK, contributed acquisition, analysis, and interpretation of data, compared to the urban settings. The acceptability among revised the manuscript critically for important intellectual content. NM, the communities was unclear from our findings. In contributed to conception, resources mobilization, supervision, revised the manuscript critically for important intellectual content. AM contributed to Yemen, as in other countries, feasibility and acceptability conception, resources mobilization, supervision and revised the manuscript studies should be conducted few months before CBS ex- critically for important intellectual content. All authors read and approved pansion in urban communities. Due to the ongoing the final manuscript. complex emergency and COVID-19 pandemic, CBS should be expanded in IDP camps in Yemen, through Funding The implementation of CBS was funded by Kuwait Fund. The funders had no creation of suspected COVID-19 and other diseases out- role in the design of the study and collection, analysis, and interpretation of breaks reporting sites. We also recommend the data and in writing the manuscript. Baaees et al. Conflict and Health (2021) 15:54 Page 15 of 15

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